Development of mass spectrometers using rectilinear ion trap analyzers

Qingyu Song, Purdue University

Abstract

The objectives of the projects described in this thesis are the development of novel ion trap mass spectrometers, in particular, using rectilinear ion trap (RIT) mass analyzers. Three mass spectrometers have been designed and constructed during the course of this research. For the first instrument, an RIT mass analyzer was incorporated into a mass spectrometer fitted with an electrospray ionization source and an atmospheric pressure interface. This ESI-RIT mass spectrometer was built for the study of biological compounds. The capabilities of the instrument were characterized using proteins, peptides and pharmaceutical drugs. In the second instrument, the RIT performance at high pressures was experimentally characterized, in terms of ion injection efficiency, mass stability, mass resolution and mass accuracy, space charge effect, mass isolation and collisional induced dissociation. The complicated role of the buffer gas inside of the RITs was explored. In the third instrument, a waveform isolation method for the mass-selective transmission of ions through quadrupole mass filters was described. The experiment was implemented in a tandem quadrupole system (two RITs serially installed) in which the first mass filter is an RIT operated in the continuous non-trapping mode to select for the transmission of one or multiple ion species of arbitrarily selected m/z value(s). The second RIT analyzer was used to verify the quality of the selection achieved using the first analyzer. A new type of tandem mass spectrometry product ion scan was demonstrated with a mixture of biological compounds. The analytical performance of the waveform isolation method was tested for simple drug mixtures and its potential for increasing overall yields in preparative mass spectrometry was explored briefly.

Degree

Ph.D.

Advisors

Cooks, Purdue University.

Subject Area

Analytical chemistry

COinS